The greatest achievement of Kate Boo’s astoundingly well-reported and surprisingly lyrical tale of the Mumbai airport slum known as Annawadi lies is what appears, at first glance, to be its shattering weakness — naivete.

Boo immortalizes her subjects and illuminates unswept corners of globalized poverty few Americans are well-informed enough to ignore. The people most likely to read behind the beautiful forevers are affluent liberals already sold on the call to redress widening wealth disparities in India, China, the U.S. and just about everywhere else.

So why did she bother? The I.M.F. spits out depressing reports on this stuff all the time. Krugman and Kristof have it covered over at the Times. Why immerse yourself, for the better part of four years no less, in the grubby lives (and the greedy bacteria) of an Indian underclass we can’t save anyway?

I’m not sure what Boo’s answer would be, but here’s mine: To repair the once-sturdy bridge between documentary journalism and the public, to walk across a neglected threshold and see if it could stand some weight. The best way to explain the monumental is to document the miniscule — that’s the way it worked for Riis, Murrow, et al. Maybe the experience will change you like it’s changed me, Boo says... Naive.

Forgetting the higher purpose, the book is a simply great Rashomon of a dozen or so interlocking, unforgettable lives. The most affecting scene in the book is probably its first. Abdul, a 16-year old Muslim scrap-picker who applies a Steve Jobs-like sense of industry and innovation to the task of monetizing discarded plastic water bottles and bike spokes, is wanted by the cops on a phony charge. They think he set the fire that killed his next door neighbor, a lippy ill-starred part-time hooker called “One Leg” for a congenital deformity.

Abdul didn’t do it. The harpy, Fatima, set herself alight with kerosene and has vengefully fingered his family out of spite — even her eight-year-old daughter, who watched her light the match, knows it. But the Mumbai cops view everything as a business opportunity, and see cash in tossing Abdul and his family into the Indian criminal courts, a comically inefficient system systematically efficient in grinding the abject into oblivion. He’d better run, and he does for a time.

We are with Abdul — Boo lets us listen to the heart beating in his ears — as he seeks shelter in the rat’s warren of huts and filthy storehouses, as he wedges himself between a wall and garbage heap to hide. Eventually, he turns himself in, guiltless, and endures months of police beatings, shakedown attempts and a shuffle between men’s and boy’s prisons. Relieved to be remanded to a juvenile facility (indoor plumbing, education classes, fewer rapists) a friendly, harried doctor offers him a thorough physical examination and an ultimatum: Give me a few thousand rupees, he asks politely, and I’ll say your sixteen. No bribe? Okay, you’re 20 — and off to the grown-up’s prison with its despoiling horrors.

In that hands of someone else, it would all seem so fake, too gripping, overly dramatic. Dickens would blush. This shit just doesn’t happen in real life. “Poor-nography” — like Jonathan Kozol’s warm-hearted but gauzy evocations of East New York and East St. Louis. That’s what we used to call it in the 90s when I worked at a little non-profit magazine in New York devoted to exposing lousy housing conditions in the city’s outer boroughs.

And Abdul’s story, if anything, is one of the more upbeat in the book. There are teenage suicides by rat poisonings, beggars run over by cars writhing in the road unaided until they expire compliantly, the water-on-rock unfairness of the neo-caste system, how dark fate of birth dooms even the most entrepreneurial slum dwellers in one of the world’s boom countries.

Boo, who spent the better part of four years in Annawadi’s hellish half-acre in the shadow of five-star hotels, writes so matter-of-factly about the details of her subject’s lives, their inner thoughts and admissions are seamlessly woven into the pattern of fact, the reader is left to assume she crayoned in the blanks of her reporting with conjecture. This is what writers for the “Wire” or any magazine scribe with a tight deadline, limited reporting and the need to scratch out narrative would do.

But it isn’t fake. It’s all real reporting.

Abdul sorts the garbage, puzzling at a pile of bottle-caps, which are notoriously hard to prep for recycling — you have to spend hours separating the different plastic bits. Sitting there, he thinks about caste and class: “[P]eople would sort themselves as he sorted his garbage, like with like.”

I am not an international development specialist or world traveler, I’m an American reporter. That’s why Boo’s self-effacing afterward, a pithy manifesto of journalism, is probably the part of beautiful forevers that sticks with me most.

“When I describe the thoughts of individuals in the preceding page, those thoughts have been related to me and my translators, or to others in our presence. When I sought to grasp, retrospectively, a person’s thinking at a given moment, or when I had to do repeated interviews in order to understand the complexity of someone’s views — very often the case — I used paraphrase… I came to my understanding of their thoughts by pressing them in repeated (they would often say endless) conversations and fact-checking interviews, often while they worked.”

Then she turns the camera for a fleeting glimpse of herself. Pale white, in perpetually ill health, so awkward she keeps stumbling in the lake of sewage that serves as they community’s sewer system, town square and fishing hole — determined to get it right.

“I had made the decision [to write the book] in the course of an absurdly long night alone in Washington D.C. Tripping over an unabridged dictionary, I found myself on the floor with a punctured lung and three broken ribs in a spreading pool of Diet Dr. Pepper, unable to slither to a phone. In the hours that passed, I arrived at a certain clarity. Having proved myself ill-suited to safe cohabitation with an unabridged dictionary, I had little to lose by pursuing my interests in another quarter — a place beyond my so-called expertise, where the risk of failure would be great but the interactions somewhat more meaningful.”

Glenn, beautifully done. Best review of the book I’ve seen and I read a few because I really loved this book. This is the kind of journalism I love, but have little practiced because I’m perpetually caught in the deadline cycle (and working on publications only interested in quick hits). I aspire to do what Boo did, without puncturing a lung. Do it for myself.